Piston packing-ring



A. B. THOMPSON.

PISTON PACKiNG RING.

APPLICATION FILED NOV- 3. 1919.

mm No 30, 1920.

' a piston ring which may curely tight, and in which the leakage is ARTHUR B. THOMPSON, on SEATTLE,

WASHINGTON.

PISTON PACKING-RING.

Specification of Letters Patent.

Patented N v. 30, 1920.

Application filed. November 3, 1919. Serial No. 335,505.

T 0 all whom it may concern Be it known that'I, ARTHUR B. THOMP- SON, a citizen of the United States, and resident of the city of Seattle, countyof King, and State of Washington, have invented certain new and useful Improvements in Piston Packing-Rings, of which the follow- 7 ing, is a specification.

My invention relates to piston rings and consists in a novel form of construction whereby I secure a superior product of this kind. I

The object of my invention is to provide be kept more seless likely to occur than rings. 1

The features of my construction which I believe to be new, and upon which I desire a patent, will be herein set forth and then particularly defined by the claims.

In the accompanying drawings I have shown the manner of constructing rings in accordance with my invention.

in f other form of Figure. 1 shows in perspective, a pair of rings associated in the relation occupied when in use, except that they are in relaxed position; that is, with ends separated as they would be when unrestrained.

Fig.2 shows a section of a cylinder and piston with a pair of rin e also in section.

Fig. 3 is a face view of one of the rings showing the 'meeting ends slightly sepa rated.

Figs. 4 and 5 are perspective views show ing the meeting ends of a ringfrom the exterior and interior, respectively.

In accordance with my invention the piston rings are made in pairs, the same consisting of an outer and an inner ring, both occupying the same groove in the piston. These rings are'both expansion rings; that is, they are cut at one point and provided with joints so that when compressed by insertion in the cylinder the ends will meet. When put together the rings are as is clearly shown in Figs. 1 and 2. The contacting surfaces of the two rings, being the inner surface of one and the outer surface of the other, are made conical, as shown at 12 in Fig. 2. These conical surfaces at the thin side of each ring are separated somewhat from the opposite face of the ring, so as to leave a surface as and of a material width, that is, a surface that is not 7 a sung fit there a sharp edge. This surface 10 of the outer ring and 20 of the inner ring, is of such s ze as to form a material contact with the slde face of the groove in the piston 3.

These rings should be made as snug a fit 1n the groove as is practicable. If made would be a small chance the side face of the ring into the space in the groove beneath or within the ring. In placing the two rings together, the joints of the respective rings would be placed at opposite sides, or at least so that they will not match with each other." p

The form of joint employed for the ends of the ring has been illustrated in the figures of the drawing. The ends of the ring are divided along a central line, and the construction at each side of this central. line differs. At the thick side of the rin is formed a projecting tongue, as 40. ubstantially half of the length of this tongue at its base is left the full thickness of the ring. The outer end of this tongue is reduced in thickness, so as to form a terminal section as 41, of much less thickness.

This construction applies to one end of the ring. The other end of the same ring has the half which lies at the thick side of the ring, cut down, so as to form a thin web 42, as is clearly shown more particularly in Fig. 4. The two portions 41 and 42,

of leakage past 7 when brought together will overlap and together will complete the closed section of this-half of the ring. When in place these two parts of the ring will at all times be overlapped and thus prevent any filtration of the steam through the ring at this point.

In the other half of the width of the ring, a cut, as 43, is made in one end and a pro jecting tongue 44 will abut against the bottom of the recess 43. However, when wear occurs these will begin to separate, and will thus leave a crack extending to the other ring. However, as the joints in the two rings do not coincide, there will be no leakage to the bottom of the groove, as one ring will be integral at the joint in the other and prevent passage of the steam or gases. The end surfaces of the rings which contact, may be cut on a bevel as is shown at 45 in Figs. 1 and 8, or' square across, as desired; this is immaterial.

The two overlapping portions 41 and 42 are placed at the thick side of the ring, be-

' may be in the remaining half of the other cause atthe opposite side of the ring it is not thick enough to form sufiiclently substantial overlapping ends. As two rings are used, one inside of the. other, the edges of each ring serves to close Whatever j oint there ring.- In consequence, leakage cannot occur to the-bottom, of the groove. The two rings having inclined or conicalcontacting sur faces, whatever steam pressure may-leak past or get to the inner side of the combined ring, Wlll serve to force the ringsoutwardand thus by reason of the inclined surfaces, push the rings laterally, so that the thick edges make a tight contact with the side walls-ofthe groove in the piston. In conse- V quence, this pressure, as well. as the-sprin'g and thus maintain tight joints. At the same byireason of the modern inclination,ofithese contacting surfaces,the rings maybe madecoinparatively th n 1n a radial direction and yet not bring their tlllhedges to a sharp edge; a

What I claim as my invention ist- 1. A piston ring composed of two expansion rings placed one within the other and having conical: contacting surfaces, the meeting ends of said rings being cut on a central plane to form two overlapping'tongues, the tongue which is at the thicker side of the ring being longer than the tongue which is at the thinner side said longer tongue hav ing an end section cut away to thin it in a radial directionand the other end of the ring being jcomplementally recessed to receive said. thinned end sectionfof the longer tongue; V

2. x piston, ringbhaving; one'peripheral surface coned and with its ends out upon a central. radial, plane to for-Intwo overlap; ping tongues, the tongue: which. isf at the thicker side of the ring being longer than the one which; is atthe thinnerside and being also cut away atiits outer endto thin it in a radial direction, the other end of the ring being complementally recessed to receive isaid thinner end of: the saidrton uea Signed at Seattle, Tashington, this 15th day of October 1919 V i ARTHUR B. THOMPSON, 

